E85 Fuel use

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chris todd
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E85 Fuel use

Post by chris todd » Wed Jul 31, 2013 11:49 am

Hi,

I'm considering A map for E85 fuel usage, from previous testing I have found that approx 35% more "global" fuel is required over unleaded petrol, could I do this using MSPB?, say for instance my current MSPB is 100 would 135 put me in the ballpark?

Any help appreciated.

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RickS
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Re: E85 Fuel use

Post by RickS » Thu Aug 01, 2013 8:40 am

Yes, the MSPB is the primary scalar and can be used to globally adjust the pulse width across the map.

You don't mention what ECU you have and are thinking of re-calibrating but depending of the ECU in question, there is usually a fuel Offset and Scalar that can be utilised and give you another form of control. If it is one of our generic ECUs, the make and model of the vehicle would help also.

Usually the final solution is a combination of MSPB, Fuel/Ignition Offset and tailored Fuel/Spark/AFR maps and tables.

As with any new fuelling strategy, I would suggest that the vehicle is mapped if you are at all unsure.
BR
Rick

chris todd
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Re: E85 Fuel use

Post by chris todd » Thu Aug 01, 2013 9:15 am

Hi Rick,

The ECU is actually an AEM subaru 2002 plug and play unit, I think you guys call it an AEM 15.
The car currently runs super unleaded or Sunoco 109 Race fuel at the drag strip, I have different calibrations for both, considering doing a calibration for E85 or methanol fuel for the track and just wondered if MSPB would be the best way to get the course adjustment somewhere near before mapping.

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RickS
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Re: E85 Fuel use

Post by RickS » Thu Aug 01, 2013 9:54 am

OK... Getting the picture...

It's certainly a starting point. We tend to see enrichment requirements of 20%-25% low end and 35%-40% at WOT/'on the floor' and to get the benefit of the (normally) higher octane rating, a little judicious ignition advance. This is just to let folks reading this know that it's not just a linear enrichment.

There are slightly different mixes of E85 (in The States it's called 'Summer/Winter Mix') but I'm sure that you're aware of this.

HTH
RickS

chris todd
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Re: E85 Fuel use

Post by chris todd » Thu Aug 01, 2013 11:59 am

Hi Rick,

Thank you, i'm aware of the different mixes etc, i'm UK based and would be using sunoco E85R which is controlled to be 85% Ethanol.

on another note, Ethanol content sensors are available with a linear 0-5v output as fitted by OEM, could additional pulsewidth/ignition be controlled based on this input to the ECU?

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RickS
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Re: E85 Fuel use

Post by RickS » Thu Aug 01, 2013 12:19 pm

Not wishing to pass-the-buck Chris but I would suggest that you have a word with AEM.

Certainly this could be 'configureable' within the GEMS architecture if the firmware were to be developed but AEM have their own development scenarios which do differ from GEMS. I am unsure what 'user' capabilities the AEM15 has but I seem to remember that it does have user definable options that maybe configureable for your purpose.

Drop AEM a line and see what they say an I will see what I can find out from this end. If I find anything, I will post it here. Apologies for not being able to give you a definitive answer.

BR
RickS

chris todd
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Re: E85 Fuel use

Post by chris todd » Thu Aug 01, 2013 5:38 pm

Thats fine Rick,
I appreciate your help :-).

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RickS
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Re: E85 Fuel use

Post by RickS » Mon Aug 12, 2013 9:24 am

Hi Again Chris,
I trust that AEM were able to shed some light on your E85 enquiries.

If it is of any help at all, I have come across a development calibration for a Subaru85, set up for E85 and looks to have options, tables and maps set in the ball-park we mentioned earlier... MSPB up to 90, enriched fuel map and recalibrated ignition etc. The tables are for MAP as load rather than TPS.

If you need some more info, let me know. Send me a PM.........
BR
RickS

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